blob: 32e6cc23bd9ad69f1f280f5148f2a5c41ffd16ea [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/ext3/xattr.c
3 *
4 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
5 *
6 * Fix by Harrison Xing <harrison@mountainviewdata.com>.
7 * Ext3 code with a lot of help from Eric Jarman <ejarman@acm.org>.
8 * Extended attributes for symlinks and special files added per
9 * suggestion of Luka Renko <luka.renko@hermes.si>.
10 * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
11 * Red Hat Inc.
12 * ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz
13 * and Andreas Gruenbacher <agruen@suse.de>.
14 */
15
16/*
17 * Extended attributes are stored directly in inodes (on file systems with
18 * inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl
19 * field contains the block number if an inode uses an additional block. All
20 * attributes must fit in the inode and one additional block. Blocks that
21 * contain the identical set of attributes may be shared among several inodes.
22 * Identical blocks are detected by keeping a cache of blocks that have
23 * recently been accessed.
24 *
25 * The attributes in inodes and on blocks have a different header; the entries
26 * are stored in the same format:
27 *
28 * +------------------+
29 * | header |
30 * | entry 1 | |
31 * | entry 2 | | growing downwards
32 * | entry 3 | v
33 * | four null bytes |
34 * | . . . |
35 * | value 1 | ^
36 * | value 3 | | growing upwards
37 * | value 2 | |
38 * +------------------+
39 *
40 * The header is followed by multiple entry descriptors. In disk blocks, the
41 * entry descriptors are kept sorted. In inodes, they are unsorted. The
42 * attribute values are aligned to the end of the block in no specific order.
43 *
44 * Locking strategy
45 * ----------------
46 * EXT3_I(inode)->i_file_acl is protected by EXT3_I(inode)->xattr_sem.
47 * EA blocks are only changed if they are exclusive to an inode, so
48 * holding xattr_sem also means that nothing but the EA block's reference
49 * count can change. Multiple writers to the same block are synchronized
50 * by the buffer lock.
51 */
52
53#include <linux/init.h>
54#include <linux/fs.h>
55#include <linux/slab.h>
56#include <linux/ext3_jbd.h>
57#include <linux/ext3_fs.h>
58#include <linux/mbcache.h>
59#include <linux/quotaops.h>
60#include <linux/rwsem.h>
61#include "xattr.h"
62#include "acl.h"
63
64#define BHDR(bh) ((struct ext3_xattr_header *)((bh)->b_data))
65#define ENTRY(ptr) ((struct ext3_xattr_entry *)(ptr))
66#define BFIRST(bh) ENTRY(BHDR(bh)+1)
67#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
68
69#define IHDR(inode, raw_inode) \
70 ((struct ext3_xattr_ibody_header *) \
71 ((void *)raw_inode + \
72 EXT3_GOOD_OLD_INODE_SIZE + \
73 EXT3_I(inode)->i_extra_isize))
74#define IFIRST(hdr) ((struct ext3_xattr_entry *)((hdr)+1))
75
76#ifdef EXT3_XATTR_DEBUG
77# define ea_idebug(inode, f...) do { \
Eric Sandeeneee194e2006-09-27 01:49:30 -070078 printk(KERN_DEBUG "inode %s:%lu: ", \
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 inode->i_sb->s_id, inode->i_ino); \
80 printk(f); \
81 printk("\n"); \
82 } while (0)
83# define ea_bdebug(bh, f...) do { \
84 char b[BDEVNAME_SIZE]; \
85 printk(KERN_DEBUG "block %s:%lu: ", \
86 bdevname(bh->b_bdev, b), \
87 (unsigned long) bh->b_blocknr); \
88 printk(f); \
89 printk("\n"); \
90 } while (0)
91#else
92# define ea_idebug(f...)
93# define ea_bdebug(f...)
94#endif
95
96static void ext3_xattr_cache_insert(struct buffer_head *);
97static struct buffer_head *ext3_xattr_cache_find(struct inode *,
98 struct ext3_xattr_header *,
99 struct mb_cache_entry **);
100static void ext3_xattr_rehash(struct ext3_xattr_header *,
101 struct ext3_xattr_entry *);
Christoph Hellwig431547b2009-11-13 09:52:56 +0000102static int ext3_xattr_list(struct dentry *dentry, char *buffer,
Adrian Bunk15633002008-04-28 02:16:06 -0700103 size_t buffer_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
105static struct mb_cache *ext3_xattr_cache;
106
Stephen Hemmingerd1f21042010-05-13 17:53:17 -0700107static const struct xattr_handler *ext3_xattr_handler_map[] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 [EXT3_XATTR_INDEX_USER] = &ext3_xattr_user_handler,
109#ifdef CONFIG_EXT3_FS_POSIX_ACL
110 [EXT3_XATTR_INDEX_POSIX_ACL_ACCESS] = &ext3_xattr_acl_access_handler,
111 [EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT] = &ext3_xattr_acl_default_handler,
112#endif
113 [EXT3_XATTR_INDEX_TRUSTED] = &ext3_xattr_trusted_handler,
114#ifdef CONFIG_EXT3_FS_SECURITY
115 [EXT3_XATTR_INDEX_SECURITY] = &ext3_xattr_security_handler,
116#endif
117};
118
Stephen Hemmingerd1f21042010-05-13 17:53:17 -0700119const struct xattr_handler *ext3_xattr_handlers[] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 &ext3_xattr_user_handler,
121 &ext3_xattr_trusted_handler,
122#ifdef CONFIG_EXT3_FS_POSIX_ACL
123 &ext3_xattr_acl_access_handler,
124 &ext3_xattr_acl_default_handler,
125#endif
126#ifdef CONFIG_EXT3_FS_SECURITY
127 &ext3_xattr_security_handler,
128#endif
129 NULL
130};
131
Stephen Hemmingerd1f21042010-05-13 17:53:17 -0700132static inline const struct xattr_handler *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133ext3_xattr_handler(int name_index)
134{
Stephen Hemmingerd1f21042010-05-13 17:53:17 -0700135 const struct xattr_handler *handler = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136
137 if (name_index > 0 && name_index < ARRAY_SIZE(ext3_xattr_handler_map))
138 handler = ext3_xattr_handler_map[name_index];
139 return handler;
140}
141
142/*
143 * Inode operation listxattr()
144 *
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800145 * dentry->d_inode->i_mutex: don't care
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 */
147ssize_t
148ext3_listxattr(struct dentry *dentry, char *buffer, size_t size)
149{
Christoph Hellwig431547b2009-11-13 09:52:56 +0000150 return ext3_xattr_list(dentry, buffer, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151}
152
153static int
154ext3_xattr_check_names(struct ext3_xattr_entry *entry, void *end)
155{
156 while (!IS_LAST_ENTRY(entry)) {
157 struct ext3_xattr_entry *next = EXT3_XATTR_NEXT(entry);
158 if ((void *)next >= end)
159 return -EIO;
160 entry = next;
161 }
162 return 0;
163}
164
165static inline int
166ext3_xattr_check_block(struct buffer_head *bh)
167{
168 int error;
169
170 if (BHDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) ||
171 BHDR(bh)->h_blocks != cpu_to_le32(1))
172 return -EIO;
173 error = ext3_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size);
174 return error;
175}
176
177static inline int
178ext3_xattr_check_entry(struct ext3_xattr_entry *entry, size_t size)
179{
180 size_t value_size = le32_to_cpu(entry->e_value_size);
181
182 if (entry->e_value_block != 0 || value_size > size ||
183 le16_to_cpu(entry->e_value_offs) + value_size > size)
184 return -EIO;
185 return 0;
186}
187
188static int
189ext3_xattr_find_entry(struct ext3_xattr_entry **pentry, int name_index,
190 const char *name, size_t size, int sorted)
191{
192 struct ext3_xattr_entry *entry;
193 size_t name_len;
194 int cmp = 1;
195
196 if (name == NULL)
197 return -EINVAL;
198 name_len = strlen(name);
199 entry = *pentry;
200 for (; !IS_LAST_ENTRY(entry); entry = EXT3_XATTR_NEXT(entry)) {
201 cmp = name_index - entry->e_name_index;
202 if (!cmp)
203 cmp = name_len - entry->e_name_len;
204 if (!cmp)
205 cmp = memcmp(name, entry->e_name, name_len);
206 if (cmp <= 0 && (sorted || cmp == 0))
207 break;
208 }
209 *pentry = entry;
210 if (!cmp && ext3_xattr_check_entry(entry, size))
211 return -EIO;
212 return cmp ? -ENODATA : 0;
213}
214
Ben Dooks381be2542005-10-30 15:02:56 -0800215static int
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216ext3_xattr_block_get(struct inode *inode, int name_index, const char *name,
217 void *buffer, size_t buffer_size)
218{
219 struct buffer_head *bh = NULL;
220 struct ext3_xattr_entry *entry;
221 size_t size;
222 int error;
223
224 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
225 name_index, name, buffer, (long)buffer_size);
226
227 error = -ENODATA;
228 if (!EXT3_I(inode)->i_file_acl)
229 goto cleanup;
Mingming Cao1c2bf372006-06-25 05:48:06 -0700230 ea_idebug(inode, "reading block %u", EXT3_I(inode)->i_file_acl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
232 if (!bh)
233 goto cleanup;
234 ea_bdebug(bh, "b_count=%d, refcount=%d",
235 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
236 if (ext3_xattr_check_block(bh)) {
Harvey Harrisone05b6b52008-04-28 02:16:15 -0700237bad_block: ext3_error(inode->i_sb, __func__,
Eric Sandeeneee194e2006-09-27 01:49:30 -0700238 "inode %lu: bad block "E3FSBLK, inode->i_ino,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 EXT3_I(inode)->i_file_acl);
240 error = -EIO;
241 goto cleanup;
242 }
243 ext3_xattr_cache_insert(bh);
244 entry = BFIRST(bh);
245 error = ext3_xattr_find_entry(&entry, name_index, name, bh->b_size, 1);
246 if (error == -EIO)
247 goto bad_block;
248 if (error)
249 goto cleanup;
250 size = le32_to_cpu(entry->e_value_size);
251 if (buffer) {
252 error = -ERANGE;
253 if (size > buffer_size)
254 goto cleanup;
255 memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
256 size);
257 }
258 error = size;
259
260cleanup:
261 brelse(bh);
262 return error;
263}
264
265static int
266ext3_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
267 void *buffer, size_t buffer_size)
268{
269 struct ext3_xattr_ibody_header *header;
270 struct ext3_xattr_entry *entry;
271 struct ext3_inode *raw_inode;
272 struct ext3_iloc iloc;
273 size_t size;
274 void *end;
275 int error;
276
Jan Kara9df93932010-01-06 21:58:48 +0100277 if (!ext3_test_inode_state(inode, EXT3_STATE_XATTR))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 return -ENODATA;
279 error = ext3_get_inode_loc(inode, &iloc);
280 if (error)
281 return error;
282 raw_inode = ext3_raw_inode(&iloc);
283 header = IHDR(inode, raw_inode);
284 entry = IFIRST(header);
285 end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;
286 error = ext3_xattr_check_names(entry, end);
287 if (error)
288 goto cleanup;
289 error = ext3_xattr_find_entry(&entry, name_index, name,
290 end - (void *)entry, 0);
291 if (error)
292 goto cleanup;
293 size = le32_to_cpu(entry->e_value_size);
294 if (buffer) {
295 error = -ERANGE;
296 if (size > buffer_size)
297 goto cleanup;
298 memcpy(buffer, (void *)IFIRST(header) +
299 le16_to_cpu(entry->e_value_offs), size);
300 }
301 error = size;
302
303cleanup:
304 brelse(iloc.bh);
305 return error;
306}
307
308/*
309 * ext3_xattr_get()
310 *
311 * Copy an extended attribute into the buffer
312 * provided, or compute the buffer size required.
313 * Buffer is NULL to compute the size of the buffer required.
314 *
315 * Returns a negative error number on failure, or the number of bytes
316 * used / required on success.
317 */
318int
319ext3_xattr_get(struct inode *inode, int name_index, const char *name,
320 void *buffer, size_t buffer_size)
321{
322 int error;
323
324 down_read(&EXT3_I(inode)->xattr_sem);
325 error = ext3_xattr_ibody_get(inode, name_index, name, buffer,
326 buffer_size);
327 if (error == -ENODATA)
328 error = ext3_xattr_block_get(inode, name_index, name, buffer,
329 buffer_size);
330 up_read(&EXT3_I(inode)->xattr_sem);
331 return error;
332}
333
334static int
Christoph Hellwig431547b2009-11-13 09:52:56 +0000335ext3_xattr_list_entries(struct dentry *dentry, struct ext3_xattr_entry *entry,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 char *buffer, size_t buffer_size)
337{
338 size_t rest = buffer_size;
339
340 for (; !IS_LAST_ENTRY(entry); entry = EXT3_XATTR_NEXT(entry)) {
Stephen Hemmingerd1f21042010-05-13 17:53:17 -0700341 const struct xattr_handler *handler =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 ext3_xattr_handler(entry->e_name_index);
343
344 if (handler) {
Christoph Hellwig431547b2009-11-13 09:52:56 +0000345 size_t size = handler->list(dentry, buffer, rest,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 entry->e_name,
Christoph Hellwig431547b2009-11-13 09:52:56 +0000347 entry->e_name_len,
348 handler->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 if (buffer) {
350 if (size > rest)
351 return -ERANGE;
352 buffer += size;
353 }
354 rest -= size;
355 }
356 }
357 return buffer_size - rest;
358}
359
Ben Dooks381be2542005-10-30 15:02:56 -0800360static int
Christoph Hellwig431547b2009-11-13 09:52:56 +0000361ext3_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362{
Christoph Hellwig431547b2009-11-13 09:52:56 +0000363 struct inode *inode = dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 struct buffer_head *bh = NULL;
365 int error;
366
367 ea_idebug(inode, "buffer=%p, buffer_size=%ld",
368 buffer, (long)buffer_size);
369
370 error = 0;
371 if (!EXT3_I(inode)->i_file_acl)
372 goto cleanup;
Mingming Cao1c2bf372006-06-25 05:48:06 -0700373 ea_idebug(inode, "reading block %u", EXT3_I(inode)->i_file_acl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
375 error = -EIO;
376 if (!bh)
377 goto cleanup;
378 ea_bdebug(bh, "b_count=%d, refcount=%d",
379 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
380 if (ext3_xattr_check_block(bh)) {
Harvey Harrisone05b6b52008-04-28 02:16:15 -0700381 ext3_error(inode->i_sb, __func__,
Eric Sandeeneee194e2006-09-27 01:49:30 -0700382 "inode %lu: bad block "E3FSBLK, inode->i_ino,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 EXT3_I(inode)->i_file_acl);
384 error = -EIO;
385 goto cleanup;
386 }
387 ext3_xattr_cache_insert(bh);
Christoph Hellwig431547b2009-11-13 09:52:56 +0000388 error = ext3_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389
390cleanup:
391 brelse(bh);
392
393 return error;
394}
395
396static int
Christoph Hellwig431547b2009-11-13 09:52:56 +0000397ext3_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398{
Christoph Hellwig431547b2009-11-13 09:52:56 +0000399 struct inode *inode = dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 struct ext3_xattr_ibody_header *header;
401 struct ext3_inode *raw_inode;
402 struct ext3_iloc iloc;
403 void *end;
404 int error;
405
Jan Kara9df93932010-01-06 21:58:48 +0100406 if (!ext3_test_inode_state(inode, EXT3_STATE_XATTR))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 return 0;
408 error = ext3_get_inode_loc(inode, &iloc);
409 if (error)
410 return error;
411 raw_inode = ext3_raw_inode(&iloc);
412 header = IHDR(inode, raw_inode);
413 end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;
414 error = ext3_xattr_check_names(IFIRST(header), end);
415 if (error)
416 goto cleanup;
Christoph Hellwig431547b2009-11-13 09:52:56 +0000417 error = ext3_xattr_list_entries(dentry, IFIRST(header),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 buffer, buffer_size);
419
420cleanup:
421 brelse(iloc.bh);
422 return error;
423}
424
425/*
426 * ext3_xattr_list()
427 *
428 * Copy a list of attribute names into the buffer
429 * provided, or compute the buffer size required.
430 * Buffer is NULL to compute the size of the buffer required.
431 *
432 * Returns a negative error number on failure, or the number of bytes
433 * used / required on success.
434 */
Adrian Bunk15633002008-04-28 02:16:06 -0700435static int
Christoph Hellwig431547b2009-11-13 09:52:56 +0000436ext3_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437{
438 int i_error, b_error;
439
Christoph Hellwig431547b2009-11-13 09:52:56 +0000440 down_read(&EXT3_I(dentry->d_inode)->xattr_sem);
441 i_error = ext3_xattr_ibody_list(dentry, buffer, buffer_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 if (i_error < 0) {
443 b_error = 0;
444 } else {
445 if (buffer) {
446 buffer += i_error;
447 buffer_size -= i_error;
448 }
Christoph Hellwig431547b2009-11-13 09:52:56 +0000449 b_error = ext3_xattr_block_list(dentry, buffer, buffer_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 if (b_error < 0)
451 i_error = 0;
452 }
Christoph Hellwig431547b2009-11-13 09:52:56 +0000453 up_read(&EXT3_I(dentry->d_inode)->xattr_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 return i_error + b_error;
455}
456
457/*
458 * If the EXT3_FEATURE_COMPAT_EXT_ATTR feature of this file system is
459 * not set, set it.
460 */
461static void ext3_xattr_update_super_block(handle_t *handle,
462 struct super_block *sb)
463{
464 if (EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_EXT_ATTR))
465 return;
466
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 if (ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh) == 0) {
Andreas Gruenbachered2908f2006-12-06 20:36:16 -0800468 EXT3_SET_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_EXT_ATTR);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh);
470 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471}
472
473/*
474 * Release the xattr block BH: If the reference count is > 1, decrement
475 * it; otherwise free the block.
476 */
477static void
478ext3_xattr_release_block(handle_t *handle, struct inode *inode,
479 struct buffer_head *bh)
480{
481 struct mb_cache_entry *ce = NULL;
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800482 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483
484 ce = mb_cache_entry_get(ext3_xattr_cache, bh->b_bdev, bh->b_blocknr);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800485 error = ext3_journal_get_write_access(handle, bh);
486 if (error)
487 goto out;
488
489 lock_buffer(bh);
490
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 if (BHDR(bh)->h_refcount == cpu_to_le32(1)) {
492 ea_bdebug(bh, "refcount now=0; freeing");
493 if (ce)
494 mb_cache_entry_free(ce);
495 ext3_free_blocks(handle, inode, bh->b_blocknr, 1);
496 get_bh(bh);
497 ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
498 } else {
Marcin Slusarz50e8a282008-02-08 04:20:13 -0800499 le32_add_cpu(&BHDR(bh)->h_refcount, -1);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800500 error = ext3_journal_dirty_metadata(handle, bh);
Andrew Morton105fd102007-03-23 00:10:02 -0700501 if (IS_SYNC(inode))
502 handle->h_sync = 1;
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500503 dquot_free_block(inode, 1);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800504 ea_bdebug(bh, "refcount now=%d; releasing",
505 le32_to_cpu(BHDR(bh)->h_refcount));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 if (ce)
507 mb_cache_entry_release(ce);
508 }
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800509 unlock_buffer(bh);
510out:
511 ext3_std_error(inode->i_sb, error);
512 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513}
514
515struct ext3_xattr_info {
516 int name_index;
517 const char *name;
518 const void *value;
519 size_t value_len;
520};
521
522struct ext3_xattr_search {
523 struct ext3_xattr_entry *first;
524 void *base;
525 void *end;
526 struct ext3_xattr_entry *here;
527 int not_found;
528};
529
530static int
531ext3_xattr_set_entry(struct ext3_xattr_info *i, struct ext3_xattr_search *s)
532{
533 struct ext3_xattr_entry *last;
534 size_t free, min_offs = s->end - s->base, name_len = strlen(i->name);
535
536 /* Compute min_offs and last. */
537 last = s->first;
538 for (; !IS_LAST_ENTRY(last); last = EXT3_XATTR_NEXT(last)) {
539 if (!last->e_value_block && last->e_value_size) {
540 size_t offs = le16_to_cpu(last->e_value_offs);
541 if (offs < min_offs)
542 min_offs = offs;
543 }
544 }
545 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
546 if (!s->not_found) {
547 if (!s->here->e_value_block && s->here->e_value_size) {
548 size_t size = le32_to_cpu(s->here->e_value_size);
549 free += EXT3_XATTR_SIZE(size);
550 }
551 free += EXT3_XATTR_LEN(name_len);
552 }
553 if (i->value) {
554 if (free < EXT3_XATTR_SIZE(i->value_len) ||
555 free < EXT3_XATTR_LEN(name_len) +
556 EXT3_XATTR_SIZE(i->value_len))
557 return -ENOSPC;
558 }
559
560 if (i->value && s->not_found) {
561 /* Insert the new name. */
562 size_t size = EXT3_XATTR_LEN(name_len);
563 size_t rest = (void *)last - (void *)s->here + sizeof(__u32);
564 memmove((void *)s->here + size, s->here, rest);
565 memset(s->here, 0, size);
566 s->here->e_name_index = i->name_index;
567 s->here->e_name_len = name_len;
568 memcpy(s->here->e_name, i->name, name_len);
569 } else {
570 if (!s->here->e_value_block && s->here->e_value_size) {
571 void *first_val = s->base + min_offs;
572 size_t offs = le16_to_cpu(s->here->e_value_offs);
573 void *val = s->base + offs;
574 size_t size = EXT3_XATTR_SIZE(
575 le32_to_cpu(s->here->e_value_size));
576
577 if (i->value && size == EXT3_XATTR_SIZE(i->value_len)) {
578 /* The old and the new value have the same
579 size. Just replace. */
580 s->here->e_value_size =
581 cpu_to_le32(i->value_len);
582 memset(val + size - EXT3_XATTR_PAD, 0,
583 EXT3_XATTR_PAD); /* Clear pad bytes. */
584 memcpy(val, i->value, i->value_len);
585 return 0;
586 }
587
588 /* Remove the old value. */
589 memmove(first_val + size, first_val, val - first_val);
590 memset(first_val, 0, size);
591 s->here->e_value_size = 0;
592 s->here->e_value_offs = 0;
593 min_offs += size;
594
595 /* Adjust all value offsets. */
596 last = s->first;
597 while (!IS_LAST_ENTRY(last)) {
598 size_t o = le16_to_cpu(last->e_value_offs);
599 if (!last->e_value_block &&
600 last->e_value_size && o < offs)
601 last->e_value_offs =
602 cpu_to_le16(o + size);
603 last = EXT3_XATTR_NEXT(last);
604 }
605 }
606 if (!i->value) {
607 /* Remove the old name. */
608 size_t size = EXT3_XATTR_LEN(name_len);
609 last = ENTRY((void *)last - size);
610 memmove(s->here, (void *)s->here + size,
611 (void *)last - (void *)s->here + sizeof(__u32));
612 memset(last, 0, size);
613 }
614 }
615
616 if (i->value) {
617 /* Insert the new value. */
618 s->here->e_value_size = cpu_to_le32(i->value_len);
619 if (i->value_len) {
620 size_t size = EXT3_XATTR_SIZE(i->value_len);
621 void *val = s->base + min_offs - size;
622 s->here->e_value_offs = cpu_to_le16(min_offs - size);
623 memset(val + size - EXT3_XATTR_PAD, 0,
624 EXT3_XATTR_PAD); /* Clear the pad bytes. */
625 memcpy(val, i->value, i->value_len);
626 }
627 }
628 return 0;
629}
630
631struct ext3_xattr_block_find {
632 struct ext3_xattr_search s;
633 struct buffer_head *bh;
634};
635
Ben Dooks381be2542005-10-30 15:02:56 -0800636static int
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637ext3_xattr_block_find(struct inode *inode, struct ext3_xattr_info *i,
638 struct ext3_xattr_block_find *bs)
639{
640 struct super_block *sb = inode->i_sb;
641 int error;
642
643 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
644 i->name_index, i->name, i->value, (long)i->value_len);
645
646 if (EXT3_I(inode)->i_file_acl) {
647 /* The inode already has an extended attribute block. */
648 bs->bh = sb_bread(sb, EXT3_I(inode)->i_file_acl);
649 error = -EIO;
650 if (!bs->bh)
651 goto cleanup;
652 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
653 atomic_read(&(bs->bh->b_count)),
654 le32_to_cpu(BHDR(bs->bh)->h_refcount));
655 if (ext3_xattr_check_block(bs->bh)) {
Harvey Harrisone05b6b52008-04-28 02:16:15 -0700656 ext3_error(sb, __func__,
Eric Sandeeneee194e2006-09-27 01:49:30 -0700657 "inode %lu: bad block "E3FSBLK, inode->i_ino,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 EXT3_I(inode)->i_file_acl);
659 error = -EIO;
660 goto cleanup;
661 }
662 /* Find the named attribute. */
663 bs->s.base = BHDR(bs->bh);
664 bs->s.first = BFIRST(bs->bh);
665 bs->s.end = bs->bh->b_data + bs->bh->b_size;
666 bs->s.here = bs->s.first;
667 error = ext3_xattr_find_entry(&bs->s.here, i->name_index,
668 i->name, bs->bh->b_size, 1);
669 if (error && error != -ENODATA)
670 goto cleanup;
671 bs->s.not_found = error;
672 }
673 error = 0;
674
675cleanup:
676 return error;
677}
678
679static int
680ext3_xattr_block_set(handle_t *handle, struct inode *inode,
681 struct ext3_xattr_info *i,
682 struct ext3_xattr_block_find *bs)
683{
684 struct super_block *sb = inode->i_sb;
685 struct buffer_head *new_bh = NULL;
686 struct ext3_xattr_search *s = &bs->s;
687 struct mb_cache_entry *ce = NULL;
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800688 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689
690#define header(x) ((struct ext3_xattr_header *)(x))
691
692 if (i->value && i->value_len > sb->s_blocksize)
693 return -ENOSPC;
694 if (s->base) {
695 ce = mb_cache_entry_get(ext3_xattr_cache, bs->bh->b_bdev,
696 bs->bh->b_blocknr);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800697 error = ext3_journal_get_write_access(handle, bs->bh);
698 if (error)
699 goto cleanup;
700 lock_buffer(bs->bh);
701
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
703 if (ce) {
704 mb_cache_entry_free(ce);
705 ce = NULL;
706 }
707 ea_bdebug(bs->bh, "modifying in-place");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708 error = ext3_xattr_set_entry(i, s);
709 if (!error) {
710 if (!IS_LAST_ENTRY(s->first))
711 ext3_xattr_rehash(header(s->base),
712 s->here);
713 ext3_xattr_cache_insert(bs->bh);
714 }
715 unlock_buffer(bs->bh);
716 if (error == -EIO)
717 goto bad_block;
718 if (!error)
719 error = ext3_journal_dirty_metadata(handle,
720 bs->bh);
721 if (error)
722 goto cleanup;
723 goto inserted;
724 } else {
725 int offset = (char *)s->here - bs->bh->b_data;
726
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800727 unlock_buffer(bs->bh);
728 journal_release_buffer(handle, bs->bh);
729
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 if (ce) {
731 mb_cache_entry_release(ce);
732 ce = NULL;
733 }
734 ea_bdebug(bs->bh, "cloning");
Josef Bacikc587f0c2008-03-19 17:00:49 -0700735 s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 error = -ENOMEM;
737 if (s->base == NULL)
738 goto cleanup;
739 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
740 s->first = ENTRY(header(s->base)+1);
741 header(s->base)->h_refcount = cpu_to_le32(1);
742 s->here = ENTRY(s->base + offset);
743 s->end = s->base + bs->bh->b_size;
744 }
745 } else {
746 /* Allocate a buffer where we construct the new block. */
Josef Bacikc587f0c2008-03-19 17:00:49 -0700747 s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 /* assert(header == s->base) */
749 error = -ENOMEM;
750 if (s->base == NULL)
751 goto cleanup;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752 header(s->base)->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC);
753 header(s->base)->h_blocks = cpu_to_le32(1);
754 header(s->base)->h_refcount = cpu_to_le32(1);
755 s->first = ENTRY(header(s->base)+1);
756 s->here = ENTRY(header(s->base)+1);
757 s->end = s->base + sb->s_blocksize;
758 }
759
760 error = ext3_xattr_set_entry(i, s);
761 if (error == -EIO)
762 goto bad_block;
763 if (error)
764 goto cleanup;
765 if (!IS_LAST_ENTRY(s->first))
766 ext3_xattr_rehash(header(s->base), s->here);
767
768inserted:
769 if (!IS_LAST_ENTRY(s->first)) {
770 new_bh = ext3_xattr_cache_find(inode, header(s->base), &ce);
771 if (new_bh) {
772 /* We found an identical block in the cache. */
773 if (new_bh == bs->bh)
774 ea_bdebug(new_bh, "keeping");
775 else {
776 /* The old block is released after updating
777 the inode. */
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500778 error = dquot_alloc_block(inode, 1);
779 if (error)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 goto cleanup;
781 error = ext3_journal_get_write_access(handle,
782 new_bh);
783 if (error)
784 goto cleanup_dquot;
785 lock_buffer(new_bh);
Marcin Slusarz50e8a282008-02-08 04:20:13 -0800786 le32_add_cpu(&BHDR(new_bh)->h_refcount, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 ea_bdebug(new_bh, "reusing; refcount now=%d",
788 le32_to_cpu(BHDR(new_bh)->h_refcount));
789 unlock_buffer(new_bh);
790 error = ext3_journal_dirty_metadata(handle,
791 new_bh);
792 if (error)
793 goto cleanup_dquot;
794 }
795 mb_cache_entry_release(ce);
796 ce = NULL;
797 } else if (bs->bh && s->base == bs->bh->b_data) {
798 /* We were modifying this block in-place. */
799 ea_bdebug(bs->bh, "keeping this block");
800 new_bh = bs->bh;
801 get_bh(new_bh);
802 } else {
803 /* We need to allocate a new block */
Akinobu Mita1eaafea2008-04-28 02:16:07 -0700804 ext3_fsblk_t goal = ext3_group_first_block_no(sb,
805 EXT3_I(inode)->i_block_group);
Mingming Cao1c2bf372006-06-25 05:48:06 -0700806 ext3_fsblk_t block = ext3_new_block(handle, inode,
807 goal, &error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808 if (error)
809 goto cleanup;
810 ea_idebug(inode, "creating block %d", block);
811
812 new_bh = sb_getblk(sb, block);
813 if (!new_bh) {
814getblk_failed:
815 ext3_free_blocks(handle, inode, block, 1);
816 error = -EIO;
817 goto cleanup;
818 }
819 lock_buffer(new_bh);
820 error = ext3_journal_get_create_access(handle, new_bh);
821 if (error) {
822 unlock_buffer(new_bh);
823 goto getblk_failed;
824 }
825 memcpy(new_bh->b_data, s->base, new_bh->b_size);
826 set_buffer_uptodate(new_bh);
827 unlock_buffer(new_bh);
828 ext3_xattr_cache_insert(new_bh);
829 error = ext3_journal_dirty_metadata(handle, new_bh);
830 if (error)
831 goto cleanup;
832 }
833 }
834
835 /* Update the inode. */
836 EXT3_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
837
838 /* Drop the previous xattr block. */
839 if (bs->bh && bs->bh != new_bh)
840 ext3_xattr_release_block(handle, inode, bs->bh);
841 error = 0;
842
843cleanup:
844 if (ce)
845 mb_cache_entry_release(ce);
846 brelse(new_bh);
847 if (!(bs->bh && s->base == bs->bh->b_data))
848 kfree(s->base);
849
850 return error;
851
852cleanup_dquot:
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500853 dquot_free_block(inode, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854 goto cleanup;
855
856bad_block:
Harvey Harrisone05b6b52008-04-28 02:16:15 -0700857 ext3_error(inode->i_sb, __func__,
Eric Sandeeneee194e2006-09-27 01:49:30 -0700858 "inode %lu: bad block "E3FSBLK, inode->i_ino,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859 EXT3_I(inode)->i_file_acl);
860 goto cleanup;
861
862#undef header
863}
864
865struct ext3_xattr_ibody_find {
866 struct ext3_xattr_search s;
867 struct ext3_iloc iloc;
868};
869
Ben Dooks381be2542005-10-30 15:02:56 -0800870static int
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871ext3_xattr_ibody_find(struct inode *inode, struct ext3_xattr_info *i,
872 struct ext3_xattr_ibody_find *is)
873{
874 struct ext3_xattr_ibody_header *header;
875 struct ext3_inode *raw_inode;
876 int error;
877
878 if (EXT3_I(inode)->i_extra_isize == 0)
879 return 0;
880 raw_inode = ext3_raw_inode(&is->iloc);
881 header = IHDR(inode, raw_inode);
882 is->s.base = is->s.first = IFIRST(header);
883 is->s.here = is->s.first;
884 is->s.end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;
Jan Kara9df93932010-01-06 21:58:48 +0100885 if (ext3_test_inode_state(inode, EXT3_STATE_XATTR)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886 error = ext3_xattr_check_names(IFIRST(header), is->s.end);
887 if (error)
888 return error;
889 /* Find the named attribute. */
890 error = ext3_xattr_find_entry(&is->s.here, i->name_index,
891 i->name, is->s.end -
892 (void *)is->s.base, 0);
893 if (error && error != -ENODATA)
894 return error;
895 is->s.not_found = error;
896 }
897 return 0;
898}
899
900static int
901ext3_xattr_ibody_set(handle_t *handle, struct inode *inode,
902 struct ext3_xattr_info *i,
903 struct ext3_xattr_ibody_find *is)
904{
905 struct ext3_xattr_ibody_header *header;
906 struct ext3_xattr_search *s = &is->s;
907 int error;
908
909 if (EXT3_I(inode)->i_extra_isize == 0)
910 return -ENOSPC;
911 error = ext3_xattr_set_entry(i, s);
912 if (error)
913 return error;
914 header = IHDR(inode, ext3_raw_inode(&is->iloc));
915 if (!IS_LAST_ENTRY(s->first)) {
916 header->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC);
Jan Kara9df93932010-01-06 21:58:48 +0100917 ext3_set_inode_state(inode, EXT3_STATE_XATTR);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918 } else {
919 header->h_magic = cpu_to_le32(0);
Jan Kara9df93932010-01-06 21:58:48 +0100920 ext3_clear_inode_state(inode, EXT3_STATE_XATTR);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 }
922 return 0;
923}
924
925/*
926 * ext3_xattr_set_handle()
927 *
Wang Sheng-Hui6e9510b2011-01-10 12:10:30 -0500928 * Create, replace or remove an extended attribute for this inode. Value
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929 * is NULL to remove an existing extended attribute, and non-NULL to
930 * either replace an existing extended attribute, or create a new extended
931 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
932 * specify that an extended attribute must exist and must not exist
933 * previous to the call, respectively.
934 *
935 * Returns 0, or a negative error number on failure.
936 */
937int
938ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
939 const char *name, const void *value, size_t value_len,
940 int flags)
941{
942 struct ext3_xattr_info i = {
943 .name_index = name_index,
944 .name = name,
945 .value = value,
946 .value_len = value_len,
947
948 };
949 struct ext3_xattr_ibody_find is = {
950 .s = { .not_found = -ENODATA, },
951 };
952 struct ext3_xattr_block_find bs = {
953 .s = { .not_found = -ENODATA, },
954 };
955 int error;
956
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957 if (!name)
958 return -EINVAL;
959 if (strlen(name) > 255)
960 return -ERANGE;
961 down_write(&EXT3_I(inode)->xattr_sem);
962 error = ext3_get_inode_loc(inode, &is.iloc);
963 if (error)
964 goto cleanup;
965
Eric Sandeend9657362009-11-16 16:27:30 -0600966 error = ext3_journal_get_write_access(handle, is.iloc.bh);
967 if (error)
968 goto cleanup;
969
Jan Kara9df93932010-01-06 21:58:48 +0100970 if (ext3_test_inode_state(inode, EXT3_STATE_NEW)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971 struct ext3_inode *raw_inode = ext3_raw_inode(&is.iloc);
972 memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
Jan Kara9df93932010-01-06 21:58:48 +0100973 ext3_clear_inode_state(inode, EXT3_STATE_NEW);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974 }
975
976 error = ext3_xattr_ibody_find(inode, &i, &is);
977 if (error)
978 goto cleanup;
979 if (is.s.not_found)
980 error = ext3_xattr_block_find(inode, &i, &bs);
981 if (error)
982 goto cleanup;
983 if (is.s.not_found && bs.s.not_found) {
984 error = -ENODATA;
985 if (flags & XATTR_REPLACE)
986 goto cleanup;
987 error = 0;
988 if (!value)
989 goto cleanup;
990 } else {
991 error = -EEXIST;
992 if (flags & XATTR_CREATE)
993 goto cleanup;
994 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995 if (!value) {
996 if (!is.s.not_found)
997 error = ext3_xattr_ibody_set(handle, inode, &i, &is);
998 else if (!bs.s.not_found)
999 error = ext3_xattr_block_set(handle, inode, &i, &bs);
1000 } else {
1001 error = ext3_xattr_ibody_set(handle, inode, &i, &is);
1002 if (!error && !bs.s.not_found) {
1003 i.value = NULL;
1004 error = ext3_xattr_block_set(handle, inode, &i, &bs);
1005 } else if (error == -ENOSPC) {
Tiger Yang7e01c8e2008-05-14 16:05:47 -07001006 if (EXT3_I(inode)->i_file_acl && !bs.s.base) {
1007 error = ext3_xattr_block_find(inode, &i, &bs);
1008 if (error)
1009 goto cleanup;
1010 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001011 error = ext3_xattr_block_set(handle, inode, &i, &bs);
1012 if (error)
1013 goto cleanup;
1014 if (!is.s.not_found) {
1015 i.value = NULL;
1016 error = ext3_xattr_ibody_set(handle, inode, &i,
1017 &is);
1018 }
1019 }
1020 }
1021 if (!error) {
1022 ext3_xattr_update_super_block(handle, inode->i_sb);
1023 inode->i_ctime = CURRENT_TIME_SEC;
1024 error = ext3_mark_iloc_dirty(handle, inode, &is.iloc);
1025 /*
1026 * The bh is consumed by ext3_mark_iloc_dirty, even with
1027 * error != 0.
1028 */
1029 is.iloc.bh = NULL;
1030 if (IS_SYNC(inode))
1031 handle->h_sync = 1;
1032 }
1033
1034cleanup:
1035 brelse(is.iloc.bh);
1036 brelse(bs.bh);
1037 up_write(&EXT3_I(inode)->xattr_sem);
1038 return error;
1039}
1040
1041/*
1042 * ext3_xattr_set()
1043 *
1044 * Like ext3_xattr_set_handle, but start from an inode. This extended
1045 * attribute modification is a filesystem transaction by itself.
1046 *
1047 * Returns 0, or a negative error number on failure.
1048 */
1049int
1050ext3_xattr_set(struct inode *inode, int name_index, const char *name,
1051 const void *value, size_t value_len, int flags)
1052{
1053 handle_t *handle;
1054 int error, retries = 0;
1055
1056retry:
Jan Kara1f545872005-06-23 22:01:04 -07001057 handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058 if (IS_ERR(handle)) {
1059 error = PTR_ERR(handle);
1060 } else {
1061 int error2;
1062
1063 error = ext3_xattr_set_handle(handle, inode, name_index, name,
1064 value, value_len, flags);
1065 error2 = ext3_journal_stop(handle);
1066 if (error == -ENOSPC &&
1067 ext3_should_retry_alloc(inode->i_sb, &retries))
1068 goto retry;
1069 if (error == 0)
1070 error = error2;
1071 }
1072
1073 return error;
1074}
1075
1076/*
1077 * ext3_xattr_delete_inode()
1078 *
1079 * Free extended attribute resources associated with this inode. This
1080 * is called immediately before an inode is freed. We have exclusive
1081 * access to the inode.
1082 */
1083void
1084ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
1085{
1086 struct buffer_head *bh = NULL;
1087
1088 if (!EXT3_I(inode)->i_file_acl)
1089 goto cleanup;
1090 bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
1091 if (!bh) {
Harvey Harrisone05b6b52008-04-28 02:16:15 -07001092 ext3_error(inode->i_sb, __func__,
Eric Sandeeneee194e2006-09-27 01:49:30 -07001093 "inode %lu: block "E3FSBLK" read error", inode->i_ino,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001094 EXT3_I(inode)->i_file_acl);
1095 goto cleanup;
1096 }
1097 if (BHDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) ||
1098 BHDR(bh)->h_blocks != cpu_to_le32(1)) {
Harvey Harrisone05b6b52008-04-28 02:16:15 -07001099 ext3_error(inode->i_sb, __func__,
Eric Sandeeneee194e2006-09-27 01:49:30 -07001100 "inode %lu: bad block "E3FSBLK, inode->i_ino,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001101 EXT3_I(inode)->i_file_acl);
1102 goto cleanup;
1103 }
1104 ext3_xattr_release_block(handle, inode, bh);
1105 EXT3_I(inode)->i_file_acl = 0;
1106
1107cleanup:
1108 brelse(bh);
1109}
1110
1111/*
1112 * ext3_xattr_put_super()
1113 *
1114 * This is called when a file system is unmounted.
1115 */
1116void
1117ext3_xattr_put_super(struct super_block *sb)
1118{
Andreas Gruenbacher8c52ab42005-07-27 11:45:15 -07001119 mb_cache_shrink(sb->s_bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001120}
1121
1122/*
1123 * ext3_xattr_cache_insert()
1124 *
1125 * Create a new entry in the extended attribute cache, and insert
1126 * it unless such an entry is already in the cache.
1127 *
1128 * Returns 0, or a negative error number on failure.
1129 */
1130static void
1131ext3_xattr_cache_insert(struct buffer_head *bh)
1132{
1133 __u32 hash = le32_to_cpu(BHDR(bh)->h_hash);
1134 struct mb_cache_entry *ce;
1135 int error;
1136
Jan Kara335e92e2008-04-15 14:34:43 -07001137 ce = mb_cache_entry_alloc(ext3_xattr_cache, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138 if (!ce) {
1139 ea_bdebug(bh, "out of memory");
1140 return;
1141 }
Andreas Gruenbacher2aec7c52010-07-19 18:19:41 +02001142 error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143 if (error) {
1144 mb_cache_entry_free(ce);
1145 if (error == -EBUSY) {
1146 ea_bdebug(bh, "already in cache");
1147 error = 0;
1148 }
1149 } else {
1150 ea_bdebug(bh, "inserting [%x]", (int)hash);
1151 mb_cache_entry_release(ce);
1152 }
1153}
1154
1155/*
1156 * ext3_xattr_cmp()
1157 *
1158 * Compare two extended attribute blocks for equality.
1159 *
1160 * Returns 0 if the blocks are equal, 1 if they differ, and
1161 * a negative error number on errors.
1162 */
1163static int
1164ext3_xattr_cmp(struct ext3_xattr_header *header1,
1165 struct ext3_xattr_header *header2)
1166{
1167 struct ext3_xattr_entry *entry1, *entry2;
1168
1169 entry1 = ENTRY(header1+1);
1170 entry2 = ENTRY(header2+1);
1171 while (!IS_LAST_ENTRY(entry1)) {
1172 if (IS_LAST_ENTRY(entry2))
1173 return 1;
1174 if (entry1->e_hash != entry2->e_hash ||
1175 entry1->e_name_index != entry2->e_name_index ||
1176 entry1->e_name_len != entry2->e_name_len ||
1177 entry1->e_value_size != entry2->e_value_size ||
1178 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
1179 return 1;
1180 if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
1181 return -EIO;
1182 if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
1183 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
1184 le32_to_cpu(entry1->e_value_size)))
1185 return 1;
1186
1187 entry1 = EXT3_XATTR_NEXT(entry1);
1188 entry2 = EXT3_XATTR_NEXT(entry2);
1189 }
1190 if (!IS_LAST_ENTRY(entry2))
1191 return 1;
1192 return 0;
1193}
1194
1195/*
1196 * ext3_xattr_cache_find()
1197 *
1198 * Find an identical extended attribute block.
1199 *
1200 * Returns a pointer to the block found, or NULL if such a block was
1201 * not found or an error occurred.
1202 */
1203static struct buffer_head *
1204ext3_xattr_cache_find(struct inode *inode, struct ext3_xattr_header *header,
1205 struct mb_cache_entry **pce)
1206{
1207 __u32 hash = le32_to_cpu(header->h_hash);
1208 struct mb_cache_entry *ce;
1209
1210 if (!header->h_hash)
1211 return NULL; /* never share */
1212 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
1213again:
Andreas Gruenbacher2aec7c52010-07-19 18:19:41 +02001214 ce = mb_cache_entry_find_first(ext3_xattr_cache, inode->i_sb->s_bdev,
1215 hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001216 while (ce) {
1217 struct buffer_head *bh;
1218
1219 if (IS_ERR(ce)) {
1220 if (PTR_ERR(ce) == -EAGAIN)
1221 goto again;
1222 break;
1223 }
1224 bh = sb_bread(inode->i_sb, ce->e_block);
1225 if (!bh) {
Harvey Harrisone05b6b52008-04-28 02:16:15 -07001226 ext3_error(inode->i_sb, __func__,
Eric Sandeeneee194e2006-09-27 01:49:30 -07001227 "inode %lu: block %lu read error",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001228 inode->i_ino, (unsigned long) ce->e_block);
1229 } else if (le32_to_cpu(BHDR(bh)->h_refcount) >=
1230 EXT3_XATTR_REFCOUNT_MAX) {
Mingming Cao1c2bf372006-06-25 05:48:06 -07001231 ea_idebug(inode, "block %lu refcount %d>=%d",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001232 (unsigned long) ce->e_block,
1233 le32_to_cpu(BHDR(bh)->h_refcount),
1234 EXT3_XATTR_REFCOUNT_MAX);
1235 } else if (ext3_xattr_cmp(header, BHDR(bh)) == 0) {
1236 *pce = ce;
1237 return bh;
1238 }
1239 brelse(bh);
Andreas Gruenbacher2aec7c52010-07-19 18:19:41 +02001240 ce = mb_cache_entry_find_next(ce, inode->i_sb->s_bdev, hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241 }
1242 return NULL;
1243}
1244
1245#define NAME_HASH_SHIFT 5
1246#define VALUE_HASH_SHIFT 16
1247
1248/*
1249 * ext3_xattr_hash_entry()
1250 *
1251 * Compute the hash of an extended attribute.
1252 */
1253static inline void ext3_xattr_hash_entry(struct ext3_xattr_header *header,
1254 struct ext3_xattr_entry *entry)
1255{
1256 __u32 hash = 0;
1257 char *name = entry->e_name;
1258 int n;
1259
1260 for (n=0; n < entry->e_name_len; n++) {
1261 hash = (hash << NAME_HASH_SHIFT) ^
1262 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
1263 *name++;
1264 }
1265
1266 if (entry->e_value_block == 0 && entry->e_value_size != 0) {
1267 __le32 *value = (__le32 *)((char *)header +
1268 le16_to_cpu(entry->e_value_offs));
1269 for (n = (le32_to_cpu(entry->e_value_size) +
1270 EXT3_XATTR_ROUND) >> EXT3_XATTR_PAD_BITS; n; n--) {
1271 hash = (hash << VALUE_HASH_SHIFT) ^
1272 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
1273 le32_to_cpu(*value++);
1274 }
1275 }
1276 entry->e_hash = cpu_to_le32(hash);
1277}
1278
1279#undef NAME_HASH_SHIFT
1280#undef VALUE_HASH_SHIFT
1281
1282#define BLOCK_HASH_SHIFT 16
1283
1284/*
1285 * ext3_xattr_rehash()
1286 *
1287 * Re-compute the extended attribute hash value after an entry has changed.
1288 */
1289static void ext3_xattr_rehash(struct ext3_xattr_header *header,
1290 struct ext3_xattr_entry *entry)
1291{
1292 struct ext3_xattr_entry *here;
1293 __u32 hash = 0;
1294
1295 ext3_xattr_hash_entry(header, entry);
1296 here = ENTRY(header+1);
1297 while (!IS_LAST_ENTRY(here)) {
1298 if (!here->e_hash) {
1299 /* Block is not shared if an entry's hash value == 0 */
1300 hash = 0;
1301 break;
1302 }
1303 hash = (hash << BLOCK_HASH_SHIFT) ^
1304 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
1305 le32_to_cpu(here->e_hash);
1306 here = EXT3_XATTR_NEXT(here);
1307 }
1308 header->h_hash = cpu_to_le32(hash);
1309}
1310
1311#undef BLOCK_HASH_SHIFT
1312
1313int __init
1314init_ext3_xattr(void)
1315{
Andreas Gruenbacher2aec7c52010-07-19 18:19:41 +02001316 ext3_xattr_cache = mb_cache_create("ext3_xattr", 6);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001317 if (!ext3_xattr_cache)
1318 return -ENOMEM;
1319 return 0;
1320}
1321
1322void
1323exit_ext3_xattr(void)
1324{
1325 if (ext3_xattr_cache)
1326 mb_cache_destroy(ext3_xattr_cache);
1327 ext3_xattr_cache = NULL;
1328}